/**
 *    Copyright (C) 2025-present MongoDB, Inc.
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    Server Side Public License for more details.
 *
 *    You should have received a copy of the Server Side Public License
 *    along with this program. If not, see
 *    <http://www.mongodb.com/licensing/server-side-public-license>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the Server Side Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#pragma once

#include "mongo/bson/bsonobj.h"
#include "mongo/bson/timestamp.h"
#include "mongo/db/exec/document_value/document.h"
#include "mongo/db/pipeline/document_source_change_stream_gen.h"
#include "mongo/db/pipeline/expression_context.h"
#include "mongo/db/pipeline/resume_token.h"
#include "mongo/util/modules.h"

#include <boost/optional/optional.hpp>
#include <boost/smart_ptr/intrusive_ptr.hpp>

namespace mongo::change_stream::topology_helpers {

/**
 * Given the 'originalAggregateCommand' and a resume token, returns a new BSON object with the same
 * command except with the addition of a resumeAfter option containing the resume token. If there
 * was a previous resumeAfter option, it will be removed.
 * The change stream version can be optionally specified to inject a specific change stream reader
 * version into the pipeline command.
 */
BSONObj replaceResumeTokenAndVersionInCommand(
    Document resumeToken,
    const BSONObj& originalAggregateCommand,
    const boost::optional<ChangeStreamReaderVersionEnum>& changeStreamVersion);

/**
 * Updates the $changeStream stage in the 'originalAggregateCommand' to reflect the start time for
 * the newly-added shard(s), then generates the final command object to be run on those shards.
 * The change stream version can be optionally specified to force a specific change stream reader
 * version on the shard.
 */
BSONObj createUpdatedCommandForNewShard(
    const boost::intrusive_ptr<ExpressionContext>& expCtx,
    const ResumeToken& resumeTokenForNewShard,
    const BSONObj& originalAggregateCommand,
    const boost::optional<ChangeStreamReaderVersionEnum>& changeStreamVersion);

/**
 * Calls createUpdatedCommandForNewShard() with the HighWaterMark ResumeToken created from the
 * 'atClusterTime' timestamp.
 */
BSONObj createUpdatedCommandForNewShard(
    const boost::intrusive_ptr<ExpressionContext>& expCtx,
    Timestamp atClusterTime,
    const BSONObj& originalAggregateCommand,
    const boost::optional<ChangeStreamReaderVersionEnum>& changeStreamVersion);

}  // namespace mongo::change_stream::topology_helpers
